import java.util.Scanner;
public class teste1 {

	/**
	 * @param args
	 */
	public static void main(String[] args) {
	
	Scanner leia = new Scanner(System.in);
	
	double p1, p2;
	
	System.out.println("p1: ");
	p1 = leia.nextDouble();
	
	double result = (p1*0.4) / 0.6;
	
	System.out.println(result);

	}

}
